1. Field of the Invention
The present invention relates to a mobile terminal for a multi-party call and a multi-party call method. More particularly, the present invention relates to a mobile terminal and a multi-party call method for controlling a multi-party call using a Dual Tone Multi Frequency (DTMF) signal.
2. Description of the Related Art
In recent years, with the rapidly increase in the use of portable terminals, such devices have become a necessity of modern life. Such portable terminals may provide all kinds of data transmission services and various additional services in addition to voice call service and providing a functional multimedia communication device.
With regard to a current synchronous portable terminal, for example, such as the majority of newer Code Division Multiple Access (CDMA) portable terminals, normally have a multi-party call function. A multi-party call is a call that is simultaneously conducted with a plurality of subscribers. A multi-party simultaneous call is advantageous that increases efficiency of a call and sometimes saves great of calling time.
In a CDMA network, a plurality of portable terminals conduct a multi-party call using a base station (BS), a base station controller (BSC), and a mobile switching center (MSC). A terminal controlling the multi-party call as the subject thereof is referred as to a ‘control terminal’, and each of the remaining terminals except for the control terminal are referred to as a ‘non-control terminal’.
The control terminal sequentially performs call connection with a plurality of non-control terminals. When the call connection is completed, the control terminal conducts a multi-party call with a plurality of connected non-control terminals. However, in a current CDMA network, when a part of the plurality of non-control terminals terminates a call, the control terminal cannot display which of the non-control terminals have terminated the call. In this case, only when a control terminal's user checks the other party's voice to see whether they are still on the line, can the user determine which non-control terminals have terminated the call and which non-control terminals continue to maintain the call.
Moreover, in the current CDMA network, the control terminal cannot selectively terminate a call with only a part of all the non-control terminals conducting the multi-party call. In order to terminate the call with the only a part of all the non-control terminals, the control terminal's user should terminate of the entire multi-party call and connect again with non-control terminals wanting to continue the call.